The attached file is an updated version of an easy-to-use cyclic voltammetry (CV) simulator written in Microsoft Excel (for details, see Brown, J. H.; J. Chem. Educ., 2016, 93 (7), 1326–1329. DOI: 10.1021/acs.jchemed.6b00052). The spreadsheet supports up to four redox couples and assumes the first process is a charge transfer. Experimental voltammograms containing up to 10,000 data points in text format can be easily copied/pasted into the spreadsheet for comparison to the simulation. The spreadsheet can be operated in protected mode or unprotected and modified as needed. The spreadsheet is provided with no guarantee and it may not be suitable for all applications. System requirements: Microsoft Windows 8.1 Office software or later.
You must list your formal redox potential (Eo') values in the proper order for your simulations to work. List Eo' values in decreasing order if reductions occur during the forward sweep. Reverse this order if oxidations occur during the forward sweep. You can then coalesce 2 adjacent peaks by exchanging their Eo' values. Set the Eo' values of unused peaks beyond the switching potential (E2) in the proper order outlined above to exclude them from the model. Set the starting potential (E1) value greater than the switching potential (E2) if reductions occur during the forward sweep. Reverse this order if oxidations occur during the forward sweep.
Added first-order intervening rate constants (kI1) between electron transfers on 12/20/16. The smaller you make a kI1 value, the slower the corresponding species is populated. The symbols kR1 and kR2 indicate first- and second-order apparent forward homogeneous rate constants that remove a corresponding species from the cycle. A simulation page for adsorbed species was added on 12/29/16 using eq. 12.5.11 in Bard, A. J.; Faulkner, L. R. in Electrochemical Methods: Fundamentals and Applications, Wiley: New York, 1980. This equation was derived for a reversible Nernst/Langmurian isotherm. A typical surface coverage (Γ*) value is 1 x 10-10 mol/cm2. This is a good starting point for the simulation of an adsorption peak. Improved the coalescence calculations on 1/10/17. The number of electrons in the rate determining step (na) controls the peak width. The total number of electrons (n) controls the current. For details, see Bard et al. Incorporated the Saul’yev RL variant to simulate Fick’s Second Law of Diffusion. This method allows the simulation of thin reaction layers. For details, see Britz, D. in Digital Simulation in Electrochemistry 3ed ed., Springer: Berlin, 2010. Reducing the variable xscale compresses the length of the diffusion grids and places the concentration points closer to the electrode surface. However, using diffusion grids that are too short or long will distort your CV waveforms, so adjust this parameter only as needed. New version (v_11) uploaded to website on 2/15/17.
Bug in the time increment calculations was corrected on 11/16/15. Bug in the concentration calculations of oxidized form of the 4th redox couple was corrected on 12/8/15. Bug in the Import data page graphics was corrected on 12/31/15. Bug in the data selection process was corrected on 4/25/16. Bug in the intervening homogeneous reactions was corrected on 11/12/16. Bug affecting the adsorption page optimization was corrected on 1/11/17.